'\" t
.\"     Title: vacuumlo
.\"    Author: The PostgreSQL Global Development Group
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: 2021
.\"    Manual: PostgreSQL 13.3 Documentation
.\"    Source: PostgreSQL 13.3
.\"  Language: English
.\"
.TH "VACUUMLO" "1" "2021" "PostgreSQL 13.3" "PostgreSQL 13.3 Documentation"
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.SH "NAME"
vacuumlo \- remove orphaned large objects from a PostgreSQL database
.SH "SYNOPSIS"
.HP \w'\fBvacuumlo\fR\ 'u
\fBvacuumlo\fR [\fIoption\fR...] \fIdbname\fR...
.SH "DESCRIPTION"
.PP
vacuumlo
is a simple utility program that will remove any
\(lqorphaned\(rq
large objects from a
PostgreSQL
database\&. An orphaned large object (LO) is considered to be any LO whose OID does not appear in any
oid
or
lo
data column of the database\&.
.PP
If you use this, you may also be interested in the
\fBlo_manage\fR
trigger in the
lo
module\&.
\fBlo_manage\fR
is useful to try to avoid creating orphaned LOs in the first place\&.
.PP
All databases named on the command line are processed\&.
.SH "OPTIONS"
.PP
vacuumlo
accepts the following command\-line arguments:
.PP
\fB\-l \fR\fB\fIlimit\fR\fR
.br
\fB\-\-limit=\fR\fB\fIlimit\fR\fR
.RS 4
Remove no more than
\fIlimit\fR
large objects per transaction (default 1000)\&. Since the server acquires a lock per LO removed, removing too many LOs in one transaction risks exceeding
max_locks_per_transaction\&. Set the limit to zero if you want all removals done in a single transaction\&.
.RE
.PP
\fB\-n\fR
.br
\fB\-\-dry\-run\fR
.RS 4
Don\*(Aqt remove anything, just show what would be done\&.
.RE
.PP
\fB\-v\fR
.br
\fB\-\-verbose\fR
.RS 4
Write a lot of progress messages\&.
.RE
.PP
\fB\-V\fR
.br
\fB\-\-version\fR
.RS 4
Print the
vacuumlo
version and exit\&.
.RE
.PP
\fB\-?\fR
.br
\fB\-\-help\fR
.RS 4
Show help about
vacuumlo
command line arguments, and exit\&.
.RE
.PP
vacuumlo
also accepts the following command\-line arguments for connection parameters:
.PP
\fB\-h \fR\fB\fIhost\fR\fR
.br
\fB\-\-host=\fR\fB\fIhost\fR\fR
.RS 4
Database server\*(Aqs host\&.
.RE
.PP
\fB\-p \fR\fB\fIport\fR\fR
.br
\fB\-\-port=\fR\fB\fIport\fR\fR
.RS 4
Database server\*(Aqs port\&.
.RE
.PP
\fB\-U \fR\fB\fIusername\fR\fR
.br
\fB\-\-username=\fR\fB\fIusername\fR\fR
.RS 4
User name to connect as\&.
.RE
.PP
\fB\-w\fR
.br
\fB\-\-no\-password\fR
.RS 4
Never issue a password prompt\&. If the server requires password authentication and a password is not available by other means such as a
\&.pgpass
file, the connection attempt will fail\&. This option can be useful in batch jobs and scripts where no user is present to enter a password\&.
.RE
.PP
\fB\-W\fR
.br
\fB\-\-password\fR
.RS 4
Force
vacuumlo
to prompt for a password before connecting to a database\&.
.sp
This option is never essential, since
vacuumlo
will automatically prompt for a password if the server demands password authentication\&. However,
vacuumlo
will waste a connection attempt finding out that the server wants a password\&. In some cases it is worth typing
\fB\-W\fR
to avoid the extra connection attempt\&.
.RE
.SH "ENVIRONMENT"
.PP
\fBPGHOST\fR
.br
\fBPGPORT\fR
.br
\fBPGUSER\fR
.RS 4
Default connection parameters\&.
.RE
.PP
This utility, like most other
PostgreSQL
utilities, also uses the environment variables supported by
libpq
(see
Section\ \&33.14)\&.
.PP
The environment variable
\fBPG_COLOR\fR
specifies whether to use color in diagnostic messages\&. Possible values are
always,
auto
and
never\&.
.SH "NOTES"
.PP
vacuumlo
works by the following method: First,
vacuumlo
builds a temporary table which contains all of the OIDs of the large objects in the selected database\&. It then scans through all columns in the database that are of type
oid
or
lo, and removes matching entries from the temporary table\&. (Note: Only types with these names are considered; in particular, domains over them are not considered\&.) The remaining entries in the temporary table identify orphaned LOs\&. These are removed\&.
.SH "AUTHOR"
.PP
Peter Mount
<peter@retep\&.org\&.uk>
